Vaccine Boosters: Unlocking Protection Against COVID Variants

The COVID-19 pandemic has been a global challenge, with over 550 million infections and 6 million deaths by July 2022. Vaccines were quickly created to fight severe illness, hospitalizations, and deaths. In a recent study, four COVID-19 vaccines were compared: BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), ChAdOx1 (Oxford/AstraZeneca), and Ad26. COV2. S (Johnson & Johnson/Janssen). Researchers looked at how these vaccines work against different COVID variants after primary and booster doses. They examined the body's antibody response against the wildtype, Alpha, Beta, Delta, and Omicron variants. The study checked how much IgG antibodies were in the body against the SARS-CoV-2 Spike protein, as well as how well antibodies could block the virus. They also tested a new method called the high-throughput ACE2 competition assay to see if it could replace the traditional pseudovirus neutralization test.The results showed big differences in how the immune system reacted with antibodies. The Ad26. COV2. S vaccine had the lowest levels of Spike-specific IgG and antibody neutralization after one dose. The BNT162b2 vaccine had intermediate levels after two doses, while the mRNA-1273 vaccine and a combination of ChAdOx1 and an mRNA vaccine had the highest levels. As the virus changed with new mutations, especially in the Omicron variant, the ability of antibodies to block the virus dropped. However, a booster dose significantly increased the levels of Spike-specific IgG and antibody neutralization, making the differences between the vaccines disappear. This study highlights the importance of booster shots and the potential of combining different vaccines for better protection against current and future COVID variants.